Comprehensive Guide for Aprilaire 400M Humidifier: Maintenance and Operation

ADDITIONAL INFORMATIONFOR ALL MODELS

Be sure to keep fireplace dampers closed when not in use. They provide an excellent escape route for heat, as well as humidity.

On occasion, indoor moisture producing activities such as clothes drying, cooking, showers, etc., may raise the RH level higher than it should be, even though the Aprilaire humidifier is not operating. Telltale indications are condensation or frost on cold surfaces such as windows, doors, walls, etc. If such condensation persists for several hours, your home should be ventilated to dissipate the potentially damaging excess moisture.

EFFECT OF WATER CHARACTERISTICS

Your humidifier is designed to operate using hot, cold, hard or mechanically softened water. (Hot water is required for Models 350 and 360.)

Water contains varying amounts of minerals. The residue remaining as a result of hard water evaporation is primarily calcium and magnesium components and is usually quite hard, scaly, and dense.

Residue from softened water tends to be soft and fluffy and has a greater volume than hard water deposits. In either case, the service life of a Water Panel evaporator will be the same. The Water Panel evaporator should be changed at least once a year with the exception of Models 400 and 400M which should be changed at least twice a heating season. In the drain- equipped models, most of the mineral solids are controlled by flushing them down the drain.

Hot supply water, 140°F maximum, is recomm ended with drain type humidifiers for increasing capacity and is required for heat pump and air handler applications.

WARNING

RISK OF SCALDING. Water temperature over 125˚F can cause severe burns and scald instantly. Shut off the hot water supply before disconnecting or tapping into any hot water supply line.

ANNUAL MAINTENANCE

For best performance, we recommend that you replace the Water Panel evaporator in your Aprilaire humidifier at least annually with the exception of Models 400 and 400M which should be changed at least twice per heating season.

The “Change Water Panel” indicator light (Digital Control only) will blink when it is time to change your Water Panel. See individual model instructions for additional maintenance.

To purchase a new Water Panel:

•Call the installer of your Aprilaire humidifier.

This information is often found on your equipment.

•Call your heating and air conditioning dealer.

•Use our “Dealer Locator” at: www.aprilaire.com

•Look in the Yellow Pages under Humidifying Apparatus or Heating & Air Conditioner Contractors.

•If none of the above is successful and you still need information, please feel free to write us.

•Purchase only Genuine Aprilaire Water Panels to maintain performance.

If your humidifier is equipped with a Digital Humidifier Control with Water Panel change indicator, after replacing the Water Panel, turn the control knob to the “Test/Reset” position until the “Humidifier On” light blinks to reset its timer. (Blower must be operating and HVAC calling for heat.) Be sure to turn the control knob back to it’s original setting. If the “Humidifier On” light continues to blink, your humidifier is in Test mode. DO NOT LEAVE THE

CONTROL IN TEST MODE OR HUMIDIFIER WILL NOT OPERATE.

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400, 600, 400M specifications

The Aprilaire 400 is a high-performance whole-home humidifier designed to enhance indoor air quality and provide superior comfort throughout your living spaces. As part of the Aprilaire family, known for their commitment to creating healthier environments, this model stands out due to its innovative features and advanced technologies.

One of the main characteristics of the Aprilaire 400 is its capacity to humidify homes effectively, covering an area of up to 4,000 square feet. This makes it ideal for large living spaces, ensuring that every room benefits from balanced humidity levels. The humidifier operates seamlessly with the home’s existing heating and cooling systems, requiring no additional maintenance, making it a hassle-free solution for homeowners.

A prominent feature of the Aprilaire 400 is its self-regulating technology. This unit uses a built-in humidistat that senses the moisture levels in your home and adjusts the humidification output accordingly. This ensures optimal humidity—typically between 30% and 50%—which can help reduce issues related to dry air, such as dry skin, irritated sinuses, and static electricity.

Another key benefit of the Aprilaire 400 is its evaporative design, which utilizes a water panel rather than a traditional water tank. This allows for efficient moisture dispersion, as the humidifier draws in dry air, passes it through the water panel, and releases it back into the living space as humidified air. The water panel is replaceable and designed for annual maintenance, promoting long-term functionality and hygiene.

The Aprilaire 400 also incorporates a simple installation process. With compatibility for various heating systems, including forced air and hydronic, it can be integrated into most homes without significant modifications. Its compact design is another advantage, ensuring it can fit unobtrusively in your home, maintaining the aesthetic of your space.

Overall, the Aprilaire 400 whole-home humidifier is a reliable solution for maintaining optimal humidity levels, fostering a healthier living environment, and enhancing overall comfort. With its advanced features, ease of use, and efficient operation, this humidifier is a smart investment for any homeowner aiming to improve indoor air quality and promote well-being.